The aim of this study was to investigate the role of Toll-like receptors 9 (TLR9) of the bovine embryonic tracheal (EBTr) cells in the innate immune response mediated by bovine herpesvirus type 1(BHV-1). Using small interfering RNA (siRNA) technology, three siRNA interference sequences target for TLR9 were designed and synthesized in this study. After siRNA-TLR9 interference, the expression levels of TLR9 gene were detected by Real-time PCR. After 48 h, the expression levels of TLR9 mRNA induced by siRNA-TLR9A, siRNA-TLR9B and siRNA-TLR9C were reduced to 60.90%, 24.05% and 40.75%, respectively. Comparing with the control group, the expression levels of TLR9 mRNA were significantly inhibited by siRNA-TLR9A fragments at 12 to 72 h (P < 0.05), and after transfecting the best fragments and infecting with BHV-1, the BHV-1 DNA copy numbers of siRNA-TLR9A group were lower than BHV-1 DNA of the control group at 6 to 72 h. The specific siRNA fragments target for TLR9 were successfully screened out in this test, and demonstrated that inhibition of TLR9 expressions could reduce the BHV-1 proliferation in EBTr cells.

According to the gene sequences analysis of foot and mouth disease virus (FMDV) in GenBank,a pair of specific primers was designed in the conserved sequence of type O FMDV P1 gene. The reaction parameters were optimized using the uniform design method to develop a two-temperature RT-PCR method for detection of type O FMDV.The results of sensitivity and specificity showed that the two-temperature RT-PCR method was only specific for type O FMDV without amplification of the other viruses. The amplified fragment was same with the expected length.The cloning and sequencing results revealed that the sequence of amplified fragment had 100% simililarity to the target sequence,and the minimum detection quantity was 1.665 pg/μL,the effective detection rate was consistent with the three step RT-PCR sensitivity test results. 54 taper toxicity test pigs were detected,and positive identification results and three-step PCR results was consistent.Compared with the three-step PCR,it could save 20 min.These results indicated that the developed two-temperature RT-PCR for detection of type O FMDV was a kind of accurate,rapid,specific and sensitive detection method.

In this study, the proliferation of goat pox virus (GPV) was researched using the recombinant GPV of TK gene insertion inactivation. Different length DNA fragments X1, X2, X3 and X4 were inserted into the transfer plasmid pTKfpgigp to constructed the recombinant transfer plasmids and these plasmids were transfected into lamb testis cells infected GPV. Recombinant GPVs of TK gene inactivation by inserting foreign DNA fragment of 2 800, 4 000, 5 200 and 7 700 bp,respectively, were generated via homologous recombination. Four recombinant GPVs (rGPV/tk^-) were obtained by selective culture and the virus titer were mensurated by 50% tissue culture infective dose. The results showed that the rGPV/tk^- virus titers were decreased obviosuly which was comparable with the wild type GPV AV41. Furthermore, the virus titer of the recombinant virus was decreased more obviously with the extension of the foreign DNA fragment. The result indicated that the proliferation of the GPV was depressed when GPV TK gene was deficient.

In order to study the genetic variation and evolution of new-type duck reovirus (NDRV) in Guangdong province, some samples (liver and spleen) were collected from different sick ducks in Guangdong province. Eight strains were initially isolated and identified. σB protein genes were amplified, cloned and sequenced by RT-PCR method,and σB protein characteristics of amino acid, antigen and genetic analysis of system evolution were compared with other strains. The results showed that the isolated viruses were the NDRV. Comparison of nucleotide sequences showed the NDRV isolated from duck in Guangdong province were more closely related to DRV reported in other parts of the country, the homology reached 96.6% to 99.5%, the NDRV isolated from duck in Guangdong province were not closely related with ARV and MDRV, the homology was 64.6% to 66.5% and 66.2% to 67.1%, respectively. Homology comparison of nucleotide between 8 strains NDRV were 97.7% to 99.7%.Compared with other strains, NDRV phosphorylation sites were less than ARV and MDRV reference strains, and the most area of the antigen index were high, similar to MDRV. Genetic evolution analysis results showed that NDRV and other domestic DRV were in the evolution of the same branch, but ARV and MDRV were in different branches. The result showed σB protein gene sequences of the NDRV were highly conserved,and NDRV isolated from Guangdong province had no significant regional differences with other regions.

This experiment was conducted to understand mosquito species, distribution of the main vector of Japanese encephalitis virus (JEV), JEV genotype and molecular characteristics in upper Pearl River region. We collected mosquito and Culicoides specimen in Shizong county, upper Pearl River region in July 2013, and these specimens were classified and identified. Meanwhile, JEV nucleotide were detected using PrM and E genes specific primers in 162 pools of mosquito and Culicoides specimen, and the positive specimens were sequencd and analyzed by bioinformatics software. Total 3 705 mosquitoes were collected from 4 collection spots, and the mosquitoes belong to 7 species in 4 generas: Culex, Anopheles, Aedes and Armigeres. In cattle pens, Anopheles Sinensis and Armigeres subalbatus were the dominant mosquito species. In sheep pens, Anopheles Sinensis and Armigeres subalbatus were the dominant mosquito species. And in pig pens, Culex tritaeniorhynchus, Anopheles Sinensis and Armigeres subalbatus were the dominant mosquito species. 4 of 162 pools mosquito and Culicoides were positive detecting by using PrM and E genes specific primers. Sequence analysis of JEV PrM and E genes results showed that 4 strains virus from Culex tritaeniorhynchus samples belonged to genotype Ⅰ JEV, and existing 15 amino acid difference sites between vaccine strain SA14-14-2 in the E gene protein, and 8 important sites which affected virus virulence did not mutant. These results suggested that there were many mosquito species in upper Pearl River region, and Culex tritaeniorhynchus, Anopheles Sinensis were dominant mosquito species in this region, and Culex tritaeniorhynchus was the main media of JEV in local region, genotypeⅠ JEV was popular in local media, and virulence of the pandemic strain did not reduce.

This study was aimed to establish a loop-mediated isothermal amplification (LAMP) assay for detection of porcine epidemic diarrhea virus (PEDV), and provide a simple, sensitive, accurate and reliable tool for diagnosis of PEDV.The conservative PEDV N gene (GenBank accession number: KT799997) of PEDV was selected as a target to design six specific primers.The reaction system and temperature of LAMP were optimized, and the LAMP method for specific amplification of PEDV was established. Results showed that the PEDV LAMP detection method was established successfully, and it could detect PEDV specifically at 60℃ for 60 min,and the detection limit was 91 copies/μL, which was one hundred-fold higher than conventional RT-PCR method.75 clinical samples were detected by LAMP and PCR, respectively, the coincidence of LAMP and PCR was about 97.3%. All the data suggested that the LAMP assay had strong specificity, high sensitivity, simple operation, low equipment requirement, and was suitable for rapid detection of PEDV clinical samples.

To investigate the relationship between the expression level of Toxoplasma gondii rhoptry neck protein 5 (TgRON5) gene in different developmental stages and the virulence of Toxoplasma gondii, the objective of this study was to examine the different expression of TgRON5 gene in different developmental stages of type Ⅱ Toxoplasma gondii PRU strain. Specific primers were designed according to the sequence of TgRON5 gene, and ACT1 gene of Toxoplasma gondii was used as a reference gene. Following the establishment of standard curve for the target and reference genes, in order to confirm the consistency of their amplification efficiency, Real-time PCR method was applied to determine and compare the expression level of TgRON5 gene in development stage which including tachyzoite, bradyzoite, non-sporulated oocyst and sporulated oocyst. The results demonstrated that TgRON5 was expressed in all developmental stages but the sporulated oocysts had the highest expression, followed by the non-sporulated oocysts, the third was tachyzoite, and the lowest was bradyzoite. It suggests that the synthesis and secretion of TgRON5 protein was closely associated with the invasiveness of the parasite. All these findings had important implications for elucidating the functions of TgRON5 involved in the invasion of Toxoplasma gondii.

In this study, the human GUCY1A3 and SFXN1 genes sequences in GenBank were chosen as probes to BLAST and got mRNA,and expressed sequence tags (ESTs) of bovine GUCY1A3 and SFXN1 genes. The bovine GUCY1A3 and SFXN1 genes were amplified by sequencing assembling of ESTs and cDNA sequences using RT-PCR. Then,we analyzed encoding proteins of bovine GUCY1A3 and SFXN1 genes with bioinformatics methods. Sequence analysis showed that the bovine GUCY1A3 gene CDS sequence was 2 076 bp,which encoded 691 amino acids, and the bovine SFXN1 gene contained a CDS region of 969 bp, which encoded 322 amino acids. The GUCY1A3 protein contained a CYCc domain, and the phosphorylation sites located in threonine, serine and tyrosine residue. The subcellular localization of GUCY1A3 protein was in the cytoplasm and it did not belong to the secreted protein. The secondary structure of GUCY1A3 protein was mainly composed of alpha helix. The SFXN1 protein contained three transmembrane helical regions and one low complexity sequence, and the phosphorylation sites located in serine, tyrosine and threonine residue. The subcellular localization of SFXN1 protein was in the endoplasmic reticulum and membrane, and it belonged to the transmembrane protein. The secondary structure of SFXN1 was mainly composed of alpha helix. The results laid the foundation for further studies of expression regulation mechanism and function of GUCY1A3 and SFXN1 genes in cattle.

In order to know the DPOL gene characterization of porcine cytomegalovirus (PCMV) (PCMV-FJ01 strain),three pairs of specific primer were designed by Oligo 7.0 software based on comparison the characterization of DPOL gene retrieved from GenBank.The target DPOL gene fragments were amplified using PCR methods with the strain PCMV-FJ01 genomic DNA. The target PCR fragments were cloned and sequenced. The assembly sequences were bioinformatics analysis. The DPOL gene of PCMV-FJ01 strain was 3 021 bp in length, coding 1 006 amino acids. The results showed that the homology of the nucleotide sequence and amino acid sequence were above 98.7% and 99.1%, respectively. Phylogenetic analysis revealed that the PCMV was closer with genus Roseolovirus rather than genus Cytomegalovirus. The results suggested that PCMV should be new species under genus Roseolovirus base on the phylogenetic relationship.

In order to analyze the immunological characteristics of lipid-associated membrane protein p60 of Mycoplasma ovipneumoniae, we cloned the N-terminal part and C-terminal part of p60 gene by PCR separately. The overlap-extension PCR was used to mutagenate nucleotides TGA (1 459－1 461 bp) to TGG. Then the PCR product was inserted to the pET-32a(+) plasmid for expression in E.coli BL21(DE3). The purified recombinant protein was analyzed by SDS-PAGE, and the recombinant N-terminal domain of p60 protein was successfully expressed with a mass of molecule of 57 ku, and a molecular of 30.5 ku of the N-terminal domain of p60 protein. Western blotting revealed that the two kinds of proteins could specifically react with positive serum, which confirmed that the recombinant N-terminal domain of p60 protein and the recombinant C-terminal domain of p60 protein both had a good reactionogenicity. This study could provide an effective reference data for screening important immunogenicity protein and establishment available diagnosis methods.

Porcine epidemic diarrhea (PED) is an acute, highly contagious enteric disease of pigs. Porcine epidemic diarrhea virus (PEDV) is the causative agent of PED. PED has caused significant economic losses to the pig industry. In this study,the purified PEDV as the coating antigen, by optimizing the ELISA reaction conditions,the indirect ELISA antibody detection method was established. The optimized reaction conditions were as follows: Antigen working concentration was 20 μg/mL; Serum sample dilution was 1:500;It was coated at 4℃ overnight; The plates were blocked by 5% calf serum incubated at 37℃ for 1 h; The secondary antibody was diluted at 1:10 000,incubated at 37℃ for 1 h. It was judged as positive when the cutoff value D_{450 nm}≥0.289,as negative when D_{450 nm}≤0.236,and as suspicious between 0.289 and 0.236.It could not react with the positive sear of other six viruses such as porcine respiratory and reproductive syndrome virus,porcine circovirus 2, classical swine fever virus, porcine parvovirus,pseudo rabies virus and foot-and-mouth disease virus. The variation coefficient of repeated test was less than 10%.74 pig serum samples from Jiangsu, Jiangxi, Fujian and Guangdong were detected,and the positive rate was 84%.It indicated that this method could be used for PEDV epidemiological surveys and diagnosis in the future.

The national standard pinella mildew element biological detection method was improved, using dry filter paper method instead of cylinder plate method, the potassium content of different samples of pinella mold were determined,and the extract composition, extraction time, the concentration of bacteria test and other factors influence on the test results of the established enramycin between concentration and the antibacterial circle diameter of linear equations was studied. The results showed that using acetone extraction liquid acetone (A:1 mol/mL HCl:water =35:12:56, pH value was adjusted to 3.0 with 1 mol/mL HCl) leaching provided sample, extraction time of 3.5 h could fully immersed test of enramycin. Use of biological indicator bacteria CMCC (B) 63501 spore count of 3.4×10⁷ per mL of the measurement of living flat dish, the formation of the inhibitory circle edge rule was clear, good accuracy. Using dry filter paper method could effectively eliminate the extraction or dilute acidic fluid itself to detect strains inhibitory effect, and the utility model had the advantages of simple operation, good repeatability. It could be used for large quantities of samples of enramycin content determination.Enramycin standard solution at concentrations for 150~500 U/mL and its bacteriostatic circle diameter and valence have good linear regression.The resulting regression equation was Y=0.00944X+11.55344, the correlation coefficient was R=0.9962, the final effective range was 0.75~2.5 U, the measured results were more close to the true value.It could be used as an efficient enduracidin determination method, worthy of promotion and use.

To explore the acting mechanism of Pueraria extract on fatty liver hepatocytes in dairy cows. The hepatocytes in dairy cows were isolated by two-step collagenase perfusion method and observed. The hepatocytes cultured in vitro were treated with different concentrations of Pueraria extract. The activities and contents of ALT, AST, TG, SOD and MDA in the hepatocytes were detected by biochemical methods. Results showed that in the administration of Pueraria extract with the concentrations of 50,100 and 500 μg/mL could extremely significantly reduce the liver cells of ALT, AST, TG, TC, MDA activity and content, increase SOD activity (P < 0.01). The Pueraria extract had significantly therapeutic effect on dairy cows fatty liver of biochemical indexes. The mechanism might be related to regulate lipid metabolism and anti lipid peroxidation.

Foot and mouth disease (FMD) is caused by foot-and-mouth disease virus (FMDV) and affects cloven hoofed animals,it is an acute and potent infectious disease which has caused great loss in some regions. Up to now, people still use vaccines to prevent and control FMD which has become the the popular ways. Prepared by virus'antigen epitopes and carried with multiple epitopes and helper epitope,the epitope-based vaccine against FMD which has caught people's attention to it owing to it has high safety and is easy to be manipulated and controlled.In recent years,the research based on epitope of FMDV has made great progress.Now we review the latest progress of the FMDV epitopes and the epitope-based vaccine against FMD in this paper, in order to provide relevant preferences for the development of the vaccines with high security and efficiency.

The aim of this experiment was to establish the oxidative stress model of immune cells in mice induced by PCV2. Optimal infection titer and time of PCV2 were selected. On the 1st,2nd and 3rd day or 1st, 3rd,5th and 7th day,Kunming mice were treated with 10⁰ PCV2 or 10^-1 PCV2 by 3 ways (intraperitoneal injection, intranasal administration and intragastrical administration). 7, 14, 21 d post administration, we killed the mice. Reactive oxygen species (ROS),total glutathione (T-GSH),reduced glutathione (GSH),oxidized glutathione (GSSG) levels and xanthine oxidase (XOD), myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activity were determined to investigate the relationship between the infection time point and the change of ROS level after PCV2 infection. Thus to establish mice immune cells oxidative stress model. The results showed that infection with 10⁰ PCV2 virus in 3 ways every day both at day 1, 2, 3 and 1 mL per mouse was the best program for the follow-up experiment. The intracellular level of ROS of mice infected with PCV2 was extremely significantly increased both at 7, 14 and 21 d (P < 0.01);7 and 14 d post infection, GSH level of PCV2 infected mice had significant difference compared with that of control group (P < 0.05). 7 d after infection, GSSG level was extremely significantly higher than that of control group (P < 0.01); 7 d after infection, T-GSH level was significantly lower than that of control group (P < 0.05), T-GSH was extremely significantly lower than that of control group at 14 d post infection (P < 0.01). XOD, MPO and iNOS activity between PCV2 infection group and blank control group were significantly different at 7 d post infection (P < 0.05). It suggested that PCV2 successfully infected mice, experimental infection programme was Kunming mice were treated with 10⁰ PCV2 by three ways (intraperitoneal injection, intranasal administration and intragastrical administration) both at the 1st,2nd and 3rd day of the experiment.The best condition to establish the oxidative stress model of immune cells in mice was using 10⁰ PCV2 to infect for 7 days.

The study was aimed to explore the effect of umbilical cord mesenchymal stem cells(UC-MSCs) and bovine mammary gland epithelial cells (BMECs) under the serum-free co-culturing condition on expression of IGF-Ⅰ. UC-MSCs and BMECs were co-cultured directly at the concentration ratios of 1:2,in control groups, UC-MSCs and BMECs were cultured alone.Using ELISA method to detect the IGF-Ⅰlevels in each group supernatant at 48 h, and two kinds of cells were separated by Transwell Chambers, the IGF-Ⅰ and IGF-ⅠR mRNA expression values of each group were estimated with Real-time PCR. The results showed that the IGF-Ⅰ concentration of UC-MSCs and BMECs mixed co-culture was significantly higher than the UC-MSCs group (P < 0.05),and extremely significantly higher than the BMECs group (P < 0.01); The IGF-Ⅰ mRNA expression of UC-MSCs/BMECs and BMECs/UC-MSCs groups were extremely significantly higher than the control group (P < 0.01),and the IGF-Ⅰ mRNA expression of BMECs/UC-MSCs group was significantly higher than the UC-MSCs/BMECs group (P < 0.05); The IGF-ⅠR mRNA expression of UC-MSCs/BMECs and BMECs/UC-MSCs groups were higher than the control group (P < 0.05;P < 0.01), BMECs/UC-MSCs group had significant difference compared with UC-MSCs/BMECs group (P < 0.05). Conclusively, the co-culture of UC-MSCs and BMECs was able to improve the IGF-ⅠR and IGF-Ⅰ mRNA expression under the serum-free condition in vitro,and the IGF-Ⅰ concentration level was correspondence with the IGF-ⅠR mRNA expression, IGF-Ⅰmainly existed in UC-MSCs.

This study was aimed to establish equine bone marrow mesenchymal stem cells(BMSCs) line and induce it to differentiate into chondrocytes. The BMSCs were collected by cutting the bone and flushing the cutting surface by PBS, and then the bone marrow was washed with PBS,the collected cells were cultured after centrifugation. The cells were purified by passaging,the stem cell properties were tested before the induction. And the cells were also appraised by the expression of the special gene of chondrocytes as well as staining the differentiated cells with Alcian blue to insure the induction was effective. The obtained BMSCs expressed Sox2 and Nanog genes, which were the stem cell special genes, and also expressed CD44, CD90 and CD105 genes, but absent of CD34 and CD45 genes. The shapes of the 3rd passage BMSCs were changed after cultured in inducing medium for a few days. Furthermore, the cells were positive to Alcian blue staining, increased expression of the Col special gene of chondrocyte day by day as well. According to this study, the BMSC line was established, and the BMSCs were induced and differentiate into chondrocytes successfully.

The experiment was designed to study the effect of okra on the growth performance,slaughter performance,meat quality and digestive enzymes activity of Danzhou chicken. 120 chicken with similar weight and 90 days old were selected randomly and divided into 5 groups with 3 replications per group and 8 chicken per replication. Control group was fed with basal diet,while chickens in groupsⅠ,Ⅱ,Ⅲ and Ⅳ were fed with the 0.5%,1.0%,1.5% and 2.0% okra added to basal diet,respectively. The trial lasted for 28 d. The results showed that compared with control group,the average daily gain of groupsⅠ,Ⅱ and Ⅲ were significantly increased (P < 0.05),the F/G were significantly decreased (P < 0.05), while group Ⅳ showed no significant significance with control group (P > 0.05);The slaughter weight, slaughter rate,eviscerated rate, half eviscerated rate and chest muscle weight of groups Ⅱ and Ⅲ were significantly increased (P < 0.05).The slaughter weight of groupⅠ was significantly increased (P < 0.05), while other indexes were showed no significant difference with control group (P > 0.05).All slaughter performance indexes of group Ⅳ were showed no significant difference with control group (P > 0.05). The drip loss rate and shear force in groups Ⅰ,Ⅱ and Ⅲ were significantly lower than control group (P < 0.05),while the cooked meat rate and pH value were significantly increased (P < 0.05).The trypsin,lipase and amylase activity of pancreas,duodenum and jejunum in groups Ⅱ and Ⅲ were significantly higher than that of control group (P < 0.05),while except lipase activity,group Ⅳ showed no significant difference with control group (P > 0.05). The results suggested that the addition of okra in the basal diet was 1.5% which could significantly improve the growth performance, slaughter performance,meat quality and digestive enzymes activity of Danzhou chicken.

Effects of aflatoxin B₁(AFB₁)-degrading agent on growth performance, nutrients metabolism and AFB₁residues in blood,liver and muscles were studied by adding it in broiler diets infected AFB₁. Seventy five 42-day-old Arbor Acres (AA) broilers were randomly allocated to 5 groups with 5 replicates per group. Broilers in group A (control group) were fed with basic diet, the diets of group B (negative control group),C, D and E were supplemented with 400, 200, 400 and 800 μg/kg AFB₁, and broilers in group C, D and E were fed with the diets containing 0.15% AFB₁-degrading agent, respectively. The experiment lasted for 30 d. Growth performance, nutrient metabolic rate,AFB₁ contents and antioxidant indices were measured at the and of experiment.The results indicated that,compared with group B, the final weight and average daily feed intake of group D were increased by 32.45% and 42.46% (P < 0.05), and the metabolic rates of organic matter, crude protein, calcium and phosphorus in other groups were significantly increased (P < 0.05),the metabolic rates of organic matter and crude protein in group D increased by 9.50% and 178.75%(P < 0.05). Liver AFB₁ content in group C was significant lower than that in group B (P < 0.05).The breast muscle AFB₁ contents in group A and C were significant lower than that in other groups (P < 0.05) at 24 h after AFB₁ administration termination. The breast muscle AFB₁ contents in group C and D were similar to the control group at 48 h after AFB₁ administration termination. Compared with group B, SOD, GSH-Px activities of serum and liver in group C, D and E were significantly increased (P < 0.05). It was concluded that adding AFB₁-degrading agent in diets could increase broiler growth and nutrient availability, accelerate AFB₁ metabolism, and reduce the harmful effect of AFB₁ on broilers.

Response surface method was used to optimize main process parameters for the polysaccharides extractions from Astragalus membranaceus fermented by probiotic FGM strain.A regression model equation was fitted.The results showed that extraction time, extraction temperature and solid-liquid ratio were significant factors on polysaccharide content fermented from Astragalus membranaceus and there was interactive effects between every two factors.Polysaccharide content was significantly affected by solid-liquid ratio,followed by extraction temperature and extraction time.The optimum conditions were found to be that the extraction time was 65 min, extraction temperature was 80℃,solid-liquid ratio was 1:9,and the polysaccharide content was 6.72 mg/mL at this condition.The results showed that the model was practical that could provide a base for exploitation new medicine.

The aim was to explore the effects of different kinds of dilution and thawing devices on the N,N-dimethylformamide (DMA) pellet frozen semen of Black Silkies. Firstly,the motility and fertility of the frozen semen thawed by different dilutions were compared;Then,the motility of the frozen semen was compared when the pellets were thawed using different tube and different number.Finally,the motility and fertility of the sperm thawed by three kinds of thawing devices (thermostat water bath,hotfunnel and hotplate ) were tested. The results showed that:①There was similar order of the sperm motility and fertility in the different dilution groups (LR > F > B > L),and there was significant difference among those groups (P < 0.05).②The motility was the best when the frozen semen was thawed with large thin-wall glass tube at 60℃.③The best temperature range of the 3 devices was different. The highest motility for thermostat water bath was 50 to 60℃ (0.51 to 0.59),and thermostat hotfunnel was 40 to 45℃ (0.42 to 0.46),while thermostat hotplate was 50 to 55℃ (0.61 to 0.63).There was no significant difference of the motility in the optimum temperature range for each device (P > 0.05).④The fertility of the different devices in their best thawing temperature was 26.91% (55℃,thermostat hotplate),23.08% (60℃, thermostat water bath), 20.93% (40℃, thermostat funnel),respectively,and there was no significant differences among those groups (P > 0.05).Therefore,the efficiency thawing condition for the Black Silkies frozen semen was the LR diluent,DMA cryoprotectant,pellet freezing,thawed in the thermostat hotplate at 54.9℃.

This experiment was amied to measure the rumen digesta passage rate and effective degradation of DM,OM and CP of finishing lambs feeding the total mixed ration (TMR).Three Kazakh wethers with (30.0±3.7)kg body weight and permanent rumen fistula were chosen and the 3×3 Latin square design was adopted.Three kinds of TMR were designed of which the energy level were same and CP levels were 11%,12% and 13%,respectively. Acetic acid ytterbium (Yb-ac) was used as solid phase chyme marker to measure the Yb element decay curve plotted by NLIN regression and figure out its outflow rate (Kp),and calculate the rumen effective degradability rate of TMR.The result showed that the Kp value of three kinds of TMR were 6.71,6.66 and 7.59 %/h,respectively. Under these conditions,the effective degradation rate of DM,OM and CP of TMR1 were 39.82%,38.58% and 43.87%,that of TMR2 were 35.70%,34.40% and 36.86%,while that of TMR3 were 42.46%、41.29% and 51.28%.The average rumen retention time were 26.49,28.98 and 21.73 h,respectively. The results of this study provided some important parameters for further evaluating DM and RUP-AA intestinal digestion of TMR.

The aim of this experiment was conducted to study the effects of fermented Atractylodes chinensis on serum immune and biochemical indexes of weaned piglets. Ninety-six Landrace ×Large White weaned piglets with weaning weight (6.0±0.5) kg were randomly allocated to 6 groups with 4 replicates per group and 4 weaned piglets per replicate. The weaned piglets were subjected to the following 6 treatments for 28 days:Control group was fed with the basal diet,groups Ⅰ and Ⅱ were fed with antibiotics and 0.2% unfermented Atractylodes chinensis in basal diet,while groups Ⅲ,Ⅳ and Ⅴ were supplemented 0.1%,0.2% and 0.3% fermentated Atractylodes chinensis in basal diet,respectively. The results showed that the immune and biochemical index of weaned piglets in fermented Atractylodes chinensis group had different degrees of improvement compared with control group and group Ⅰ.In the whole experimental stage,comparing with control group,the serum IgA,IgG,IgM,TP and ALB of weaned piglets in group Ⅳ were increased 10.5%,10.0%,7.8%,21.0% and 15.6%,respectively,and the difference were significant (P < 0.05),and serum ALT content was significantly reduced 20.4% (P < 0.05).Compared with group Ⅰ,the serum IgA,IgG,IgM and TP of weaned piglets in group Ⅳ were increased 7.1%,3.8%,3.8% and 12.6%, respectively,the difference were significant (P < 0.05),while the serum ALB, AST and BUN of group Ⅳ were increased 1.0%, 9.5% and 15.0%, and the difference were not significant (P > 0.05), and serum ALT content was reduced 9.4% compared with the antibiotics group (P > 0.05).

This experiment was conducted to investigate the effects of energy level on growth performance,slaughter performance,ruminal fermentation parameters and the number of several rumen microorganisms in house-fed yaks. Single factor randomized block design was adopted in this study,and sixty healthy 3-year-old Maiwa yaks with an average body weight of (192.66±3.64) kg were randomly divided into 3 groups with 20 replicates per group and 1 yak per replicate. Diets for all groups had the same crude protein content (14.81%) and different net energy levels for gain (NE_g) with 4.17(LE),4.48(ME) and 4.79(HE) MJ/kg,respectively. The experiment was lasted for 97 days (7-day pretrial period and 90-day feeding trial). The results showed that compared with LE group,average daily gain (ADG) of ME (1 099.89 g/d) and HE (1 019.02 g/d) were increased by 27.26%(P < 0.01) and 17.90%(P < 0.01),respectively,the F/G trended to be significantly decreased (P=0.073) and slaughter rate trended to be significantly increased (P=0.092) than that of LE group. However,no significant difference was found on the dry matter intake (DMI) and net meat percentage among all treatment groups (P > 0.05).With the increase of diet energy level, pH in yak rumen tended to decrease significantly (P=0.064), and that of ME group was the lowest.The increase of diet energy level tended to significantly affect the isobutyric acid concentration (P=0.063) and the ratio of acetic acid to propionic acid (P=0.074).Total volatile fatty acids (TVFA) and acetic acid concentration of ME group were significantly higher than the other two groups (P < 0.05),of which the valeric acid concentration was extremely significantly increased with the increase of the diet energy level (P < 0.01).Increasing dietary energy level had a trend to decrease the relative content of R.flavefaciens,but there was no significant effects on the relative content of R.albus and F.succinogenes (P > 0.05). In conclusion,we recommend 4.48 MJ/kg (DM basis) as a diet appropriate NE_g level for the barn feeding of fattening yak under this experimental condition.

The feed antibiotics are long added into the feed as growth promoters,resulting in a series of problems,such as drug residues in livestock products,drug-resistant strains emergence and environmental pollution.Probiotics fermented feed can reduce the anti-nutritional factors in raw materials, produces beneficial metabolites, soluble peptides and other small molecules,that will enhance the nutritional level of feed, play a role in promoting growth and improving immune function.The present studies have showed that probiotics fermented feed will be one of the potential solutions. Therefore, this paper will be focused on the effects of probiotic fermented feed on piglet growth and immunity, which will provide the theoretical base for further study in this field.

The experiment was conducted to study the influence of Lactobacillus plantarum (LP) on production performance, egg and feces Salmonella enteric (SE) residues of SE-infected hens. 144 fifty-week-old Nongda No.3 hens were randomly allocated to 4 treatments with 4 replicates of 9 hens each. The hens in blank control and positive control groups were fed the basal diet, terramycin group, the basal diet with terramycin (5 mg/kg), LP group, the basal diet with Lactobacillus plantarum (10⁹CFU/kg). The hens in positive control, terramycin and LP groups were oral inoculated with 1 mL SE (10⁹CFU/mL) on 22 and 24 d. The experiment lasted for 50 d. Before being vaccinated, the production performance of each group showed no significant difference (P > 0.05); After being vaccinated, in early period, compared with blank control group, the average egg weight significantly decreased (P < 0.05), the feed-egg ratio significantly increased (P < 0.05), and the SE content of eggs and feces significantly increased (P < 0.05) in positive control group. Compared with positive control group, the average egg weight in terramycin group and LP group increased by 5.43% and 9.64% respectively (P < 0.05), while the feed-egg ratio decreased by 11.51% (P < 0.05) and 5.16% (P > 0.05) respectively. In later period, the feed-egg ratio in LP group decreased by 9.96% (P < 0.05), SE content of eggs and feces in LP group decreased by 43.17% and 23.93% respectively (P < 0.05). The production performance and E. coli, SE-carrying rates of eggs had no significant difference among the blank control, LP and terramycin groups (P > 0.05). The results indicated that, supplemented with Lactobacillus plantarum or terramycin could improve the production performance, reduce the SE content in eggs and feces, and improve the ability to resist infection in hens. Because Lactobacillus plantarum had the characteristics of no pollution and no residue, it could be used as a kind of ideal substitute for antibiotics in poultry production.

In order to obtain the important functional genes related to prolificacy,transcriptome of gonadal axis 5 Bamei mutton with high repeoduction and 4 Bamei mutton with low reproduction were analyzed using RNA-Seq technology. The sequencing data was analyzed by bioinformatics methods. After quality control, 112 Gb clean data were obtained from 27 libraries of hypothalamus, pituitary and ovary. The differential expression analysis underlined 111 genes highly expressed in the hypothalamus, 97 in the pituitary and 182 in the ovary between twinning group and single lambs;106 genes lower expression in the hypothalamus,142 in the pituitary and 67 in the ovary between twinning group and single lambs. Functional enrichment analysis revealed that neuroactive ligand-receptor interaction signaling pathway played an important role in the hypothalamic-pituitary-ovarian axis regulation of ovulation and follicular development. Comparative transcriptomic studies for different lambing number Bamei mutton sheep gonadal axis prodeced all transcript information, provided a list of functiona genes for influencing litter size, enriched and supplemented the sheep genome information, laid the theoretical basis for further elucidation the molecular mechanism of sheep fecundity differences.

The whole genome sequencing and related genetic map have been declared completed in chicken and many species. Because of the limitations of annotation methods, there are many missing novel genes and annotation errors of existed genes. RNA-Seq is a method for transcriptome studies based on second generation sequencing. In this study,we had sequenced cDNA library that were transcribed from all RNAs in ovaries of eight 300 days old Jinghai Yellow chickens(unanimous weight and the same rearing conditions, but there were difference on the number eggs and evenly divided into two groups: High laying performance and low laying performance) by using high-throughput sequencing technologies. 4 431 new transcripts were found by analysing transcriptome data, and many potential novel genes were found and annotated by comparing all new transcripts with GO, NR, Swiss-Prot and KEGG databases. Our work provided basic data for the further improvement of chicken genome and mining functional genes.

To reveal the molecular mechanism involved in different number of ovulation between hyperprolific and ordinary sows, forward and reverse subtracted cDNA libraries were constructed to screen differentially expressed genes in medium ovarian follicles at 4th day during follicular phase of estrous cycle between Meishan and Duroc sows. The differentially expressed genes selected were demonstrated by Real-time PCR and cluster analysis was performed through DAVID. The results showed that a total of 148 and 75 non-redundant ESTs were isolated from the SSH library of Meishan and Duroc sows M2 follicles, including 125 and 60 known genes, respectively. The results of Real-time PCR were consistent with the screening results. GO analysis indicated that these genes were involved in regulation of metabolic process, cell cycle, biosynthetic process, intracellular transport, steroid hormone receptor and stimulus. KEGG pathway analysis defined 6 genes involved in TGF-beta signaling pathway, 5 genes in oocyte meiosis pathway, 7 genes in steroid hormone receptor signaling pathway. Genes controlling TGF-beta signaling pathway were considered to play an important role in regulating follicle development. The research would be helpful for further studying the follicular development and the genetic mechanism on reproductive traits.

The study was aimed to investigate the protein location and the transcriptional expression of C3 on mouse normal hatched blastocysts and dormant embryos before and after cryopreservation, and to provide theoretical basis for elucidating the regulation mechanism of mammalian embryos during antifreeze. The ICR female mouse were selected, normal hatched blastocysts were collected from 5th pregnant mouse and dormant embryos were obtained from mouse delayed implantation model, then the confocal and Real-time PCR were used to detect ICC and relative expression of C3 mRNA on each group. The results showed that C3 were both expressed on transcriptional and translational levels in mouse normal hatched blastocysts and dormant embryos before and after cryopreservation;The relative expression of C3 mRNA in normal hatched blastocysts was significantly up-regulated after cryopreservation (P < 0.05);The relative expression of C3 mRNA in dormant embryos was significantly down-regulated after cryopreservation (P < 0.05);The relative expression of C3 mRNA in dormant embryos before cryopreservation was significantly higher than the normal hatched blastocysts before cryopreservation (P < 0.05);The relative expression of C3 mRNA in dormant embryos after cryopreservation was significantly lower than the normal hatched blastocysts after cryopreservation (P < 0.05). The results showed that the transcriptional down-regulated expression of C3 in embryos had a positive effect on the antifreeze of embryos, and C3 gene might be involved in the regulation of embryo freezing-thawing process.

This study was aimed to separate Bacillus from healthy pig feces by high temperature treatment method and conventional anaerobic bacteria isolated method, and through the cultivation of traits, biochemical tests, PCR, bowel tolerance, antibacterial activity and vaccinated animals and other screening methods to identify stable properties and probiotic Bacillus. As a result, a total of six strains of Bacillus, which were one strain of huge Bacillus, one strain of Death Valley Bacillus, two strains of Bacillus amyloliquefaciens and two strains of Bacillus subtilis. Isolates were resistant to polymyxin and penicillin, were more sensitive to the other 12 kinds of commonly used drugs, and had better bacteriostatic action to pathogenic E.coli and Staphylococcus aureus. Four kinds of Bacillus were available under acidic, high temperature conditions and bile salts, in particular Bacillus megaterium and Bacillus subtilis were strong tolerance. Those isolated Bacillus were not pathogenic to mice, wherein Bacillus megaterium and Death Valley Bacillus had a more significant role in promoting the growth of animals. Finalized, the Bacillus megaterium and the Death Valley Bacillus could initially be as probiotic Bacillus choice.

To further identify the pathogenic strains and analyze their antibiotic resistance, the methods of pathogen isolating, the methods of Gram staining, biochemical tests and 16S rRNA PCR amplification, virulence tests, drug sensitive tests, virulence genes and resistance genes PCR amplification were used. The results showed that the strain was Gram-positive and revealed positive after reacting with 6.5% NaCl, melibiose, sucrose and etc., while revealed negative reactions with VP, hippurate, arabinose and etc.. It showed 100% similarity with Enterococcus feacium 16S rRNA gene sequence in GenBank after PCR amplification of 16S rRNA gene and BLAST alignment. It was found severe pathogenicity after virulence tests in mice. The strain was highly resistant to oxacillin, penicillin G of β-lactam antibiotics and norfloxacin, ciprofloxacin, levofloxacin of quinolones antibiotics and tetracycline, while was sensitive to antibiotics of erythromycin, vancomycin and clindamycin. It revealed that virulence factor genes Asal, cylA, acm and resistance genes TetM, ant(6)-Ⅰ, aac(6')-aph (2"), ermB showed positive. The results showed that the bacteria was Enterococcus feacium, it had a strong pathogenicity and severe drug resistance, which might be related to the highly positive rates of virulence genes and drug resistance genes.

In order to understand the molecular mechanism of host susceptibility differential to highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRSV) infection among three breeds of pig, Tibetan pig,ZangMei Black and Yorkshire,the mRNA level of five reported PRRSV receptor genes (HSPG2,SIGLEC1,CD163,VIM and NMMHC-ⅡA) expressed in lung were investigated on 0,4, 7 and 14 days post infection (dpi) with HP-PRRSV JXA1 isolate.The Real-time RT-PCR results showed that the expression of HSPG2 in Tibetan pig increased significantly on 4 and 14 dpi and decreased significantly on 7 dpi compared with the expression on 0 dpi (P < 0.05), and its expression in ZangMei Black on 14 dpi was significantly higher than that of on 7 dpi (P < 0.05);An increased expression of SIGLEC1 in Tibetan pig was observed on 4 and 14 dpi (P < 0.05), and a decreased expression of the same gene was detected in Yorkshire on 4,7 and 14 dpi (P < 0.05);The expression of CD163 elevated significantly on 14 dpi in both Tibetan pig and ZangMei Black (P < 0.05), however its expression reduced significantly on 7 and 14 dpi in Yorkshire (P < 0.05); The expression of VIM gene was significantly higher on 7 dpi in Tibetan pig and significantly lower on 7 dpi in Yorkshire (P < 0.05); And the expression of NMMHC-ⅡA was significantly higher on 4 dpi in ZangMei Black, which was also significantly higher in Yorkshire on 4 and 14 dpi (P < 0.05).In conclusion, SIGLEC1 and VIM might be important genes to influence the host resistance of Tibetan pig,ZangMei Black and Yorkshire to HP-PRRSV infection.

The study was aimed to select the best composite bait adjuvants and oral vaccine prescriptions, and test the immune mice serum IgG and IgA antibody titer in the gut. Using the beef powder, chicken powder, fish powder, milk powder and blood meal as the main raw material, and bacterial lipopolysaccharide, zinc hydroxide, LBP, mannan oligosaccharide as vaccine adjuvant,through orthogonal experiment method composited immunologic adjuvant and oral rabies vaccine bait SRV₉, after mixing virus oral immunization of test mice. The optimized composite adjuvant party was bacterial lipopolysaccharide 100 μg, zinc hydroxide 0.8 mg, LBP 50 mg, mannan oligosaccharides 10 mg, serum IgG antibody content of mice immunized with 3.24 mg/L, intestinal IgA antibody content of 1.56 ng/mL.In feeding trials of the vaccine in the bait, wolves, foxes, dogs and cats feed on the bait fish flavor highest rate, followed by dried blood and creamy bait; After bait mixed with the rabies virus SRV₉ oral immunization of mice 28 d the serum IgG was in average of 1.20 U/L. This experiment screened preparation of bait fish meat with high intake, was suitable for wild carnivorous animal oral vaccine preparation, and screened the compound oral vaccine adjuvant,it would increase the immune effect of rabies virus SRV₉ strain and provide the necessary technical support for further research and development of recombinant attenuated rabies vaccine.

To prepare the monoclonal antibodies (MAbs) against DHAV-1a, hybridomas were produced by fusing SP2/0 cells with spleen cells from mouse immunized with DHAV-1a pGEX-VP1 recombinant protein. Two hybridomas stablely secreting MAbs against VP1 protein were identified by indirect ELISA detection with DHAV-1a as coating antigen. The ascetic fluids of MAbs were 1:3.2×10⁴ and 1:2.0×10⁶, respectively. The MAbs were IgG1 with κ chain. Western blotting analysis showed that the MAbs could recognize the recombinant VP1 protein and DHAV-1a. The neutralization tests showed that one MAb (5G3) had better neutralization activity. Therefore, the results showed that the ELISA titers and specialities of two MAbs were very good, with excellent stability. In addition, they all had cross interaction with DHAV-1 and DHAV-1a, one of which had good neutralization activity.

To understand the infection of main internal parasites in yaks, total of 402 fecal samples of yaks were collected from Hongyuan county in Aba prefecture and Litang county in Ganzi prefecture, the morphological characteristics of 4 kinds of internal parasitic eggs or oocysts were observed and the numbers of them were counted using the modified Liao's counting method. The results showed that in yaks of Hongyuan county, the average infection intensities of EPG or OPG of nematodes, cestodes, trematodes and coccidian were 11.59, 23.77, 42.45 and 14.72, respectively, and the total number of infections was 92.53 (48.91 to 154.90); The average infection rates of eggs or oocysts of these 4 kinds of parasites were 18.01%, 36.62%, 44.68% and 17.37%, respectively, and the total infection rate was 76.39%, which proved that trematodes was the dominant parasitic species and cestodes was also an important one in this area. In yaks of Litang county, the average infection intensities of EPG or OPG of nematodes, cestodes, trematodes and coccidian were 52.38, 13.10, 20.24 and 1.19, respectively, and the total number of infections was 86.90, the average infection rates of eggs or oocysts of these 4 kinds of parasites were 52.38%,19.05%,23.81% and 2.38%, respectively, the total infection rate was 78.57%, which proved that nematodes was the dominant parasitic species in this area. The infection patterns of internal parasitic eggs or oocysts in yaks in Hongyuan and Litang county were all mainly the single and double infection, the sums of these two patterns were 69.31% and 78.57%, respectively, which accounted for 90.73% and 100% of the total infection rate, respectively. The results in this paper showed that the parasitic disease in yaks was still an important disease harmful to yak production and herdsman health, meanwhile these results enriched the epidemiological data of the internal parasitic disease of yaks in Northwest plateau of Sichuan province and provided a theory basis for prevention and control of parasitic diseases in yaks in this area.

The study was aimed to explore the antioxident function of sulforaphane (SFN) on the leydig cells of cadmium (Cd) exposured mice.Cd and SFN were added to the cell culture medium of TM3 cell, half inhibitory concentration (IC₅₀) of Cd and SFN safe dose range were determined.The tested model was set up,and the relative survival rate of TM3 cells, lactate dehydrogenase (LDH) activity and cell antioxidant levels were determined to study the antioxident function of SFN to cadmium exposured mice.The results showed that:①With the increase of Cd concentration,the relative survival rate of TM3 cells was decreased,and the IC₅₀ of Cd was 51.4 μmol/L;Within a certain concentration range,SFN could increased the cells survive rate,but there was toxicity when the SFN concentration was more than the scope,and the greater the concentration,the greater the toxicity. At experimental condition,SFN safety concentration were 2.5,5 and 10 μmol/L.②Compared with the control group,the GSH content,the T-SOD and GSH-Px activities in Cd group were significantly or extremely significantly decreased (P < 0.05;P < 0.01),and the LDH activity,the MDA content were increased.Additionally,the LDH activity and MDA content of SFN groups were decreased,while others three indexes were increased. Compared with Cd group,the GSH content,the T-SOD and GSH-Px activities of Cd+SFN groups were significantly or extremely significantly increased (P < 0.05;P < 0.01),however,the LDH activity,MDA content were decreased. The result indicated that SFN had the antagonism effect on toxicity of Cd in TM3 cell.

To establish UV fingerprint method of measuring Gongyingqinglan mixture quality,UV fingerprints were got using ultraviolet spectrophotometer scanning ten Gongyingqinglan mixture,and the correlation coefficient method was used to calculate the similarity between Gongyingqinglan mixture sample fingerprints and contrasted fingerprint. The results showed that the UV fingerprint absorbance of samples that chlorogenic acid content conformed with the provisions were 0.165-0.265 Abs (317.00 nm),0.162-0.285 Abs (282.00 nm) and 0.137-0.240 Abs (259.00 nm),and the fingerprint similarity was above 0.910.While the UV fingerprint absorbance of samples that chlorogenic acid content was not in conformity with the provisions did not meet this condition of 0.165-0.265 Abs (317.00 nm),0.162-0.285 Abs (282.00 nm) and 0.137-0.240 Abs (259.00 nm) or the fingerprint similarity were below 0.910.This method could be used to control the quality of the Gongyingqinglan mixture.

Cell line was an important carrier for the isolation and culture of animal viruses.In the research, modern commercial piglet kidney was taken as the raw material in order to cultivate a new cell line for isolating and culturing animal viruses. By trypsin digestion and differential velocity adherent combination method,porcine kidney epithelial cells were separated and purified,and then continuously subcultured in vitro. The results showed that a new cell strain named SDPK-D had been serially passaged for 90 generations.The doubling time of SDPK-D cell strain F33 and F83 were 40.9 and 32.7 h,respectively;While the cell viability were 97.55% and 98.86%,the cell adherent rate at the 8 h were 91.67% and 97.06%,respectively. Obvious cytopathic effect appeared after inoculating with PRV,SIV and PEDV positive samples. For the first time, a new cell strain from modern pig named SDPK-D was successfully cultivated,which was sensitive for several animal viruses.It could provid a new selection for the isolation and culture of virus.

The purpose of this study was to indicate the antibacterial effect of traditional Chinese medicine Radix dichroa powder (RDP) in vitro. Minimal inhibitory concentration (MIC) of RDP for 12 pathogens were determined by two fold dilution method and agar dilution method, and the dose-effect relationship of antibiotic effect was studied, and the antimicrobial effect was also observed by Oxford-cup method. The results from two fold dilution method indicated that RDP had stronger inhibited effect to Streptococcus and Bacillus subtilis (MIC were from 15.6 to 62.5 mg/mL) than that of S. aureus (MIC was about 250 mg/mL), Enterobacteria (MIC was about 500 mg/mL) and fungi (MIC > 500 mg/mL); The results of agar dilution method showed that RDP had some antibacterial activities on Proteusbacillus vulgaris, Candida albicans And aspergillus niger, MIC was about 500 mg/mL, while it had weak antibacterial effect on other pathogens (MIC > 500 mg/mL). The results of Oxford-cup method showed that RDP (500 mg/mL) had some degree antimicrobial effect on pathogens, and the bacteria-inhibiting ring diameter of RDP not exceeded 10 mm, while drug-action ring was observed obviously around the Oxford-cup, and the number of bacteria was significantly decreased within the ring. In conclusion, RDP had some degree antibacterial effect on common pathogens, but the effects were not strong because of charicteristics of RDP itself and lower effective content.

To investigate the effects of Ferula sinkiangensis polysaccharides (FSP) on cell proliferation of chicken splenic lymphocytes and peripheral lymphocyte in vitro. By the method of water extract-alcohol precipitation,total Ferula sinkiangensis polysaccharide (FSP_t) and 30%,50%,70% gradient alcohol precipitation of polysaccharides (FSP₃₀,FSP₅₀ and FSP₇₀) were extracted, and detected by phenol-sulfuric acid method and infrared spectroscopy method. The safe concentration of all classifications of polysaccharide were detected and the effect of FSP on lymphocyte proliferation of chicken spleen and peripheral blood were measured by MTT method. The results showed that the absorption peak of FSP were conformed to belong by polysaccharide compounds. Peripheral blood T lymphocyte proliferation test indicated that FSP_t,FSP₃₀ and FSP₇₀ alone or cooperated with PHA could stimulate T lymphocyte proliferation under a certain concentration,and FSP_t showed a better proliferation effect. Spleen B lymphocyte proliferation test showed that FSP_t,FSP₃₀ and FSP₇₀ alone or cooperated with LPS could stimulate B lymphocyte proliferation under a certain concentration,FSP_t and FSP₇₀ showed a better proliferation effect. In conclusion,FSP showed the strong effect on lymphocyte proliferation of chicken spleen and peripheral blood in vitro,and that would be the materials for further research.

The homeobox (HoX) gene that controls cell differentiation and morphological development is an important gene having highly genetic level. These genes highly express in the embryonic period and affect the embryonic development and differentiation and control the development of body structure and organs. The homeobox gene Prrx includes three types, Prrx1, Prrx2 and Prrx3, this family gene plays an important role in the development of cleft palate, jaw, extremities, tibia and fibula in human and mouse, and is also closely related to the development of the brain, spinal cord, nerve, heart and other organs. The Prrx1 and Prrx2 are mainly involved in the development of bone and cardiovascular system in embryo, such as limb, craniofacial, cartilage and arteries, and Prrx3 is mainly involved in the development of embryonic cartilage, bone, brain, spinal cord and so on. This paper reviewed the functions of Prrx gene, so as to provide certain references for research on the gene functions and prevention and control of related diseases.

An acute infectious diseases occurred in a koi farm in Fangshan district, Beijing, and it resulted in mortalities of more than 50%.The main symptoms of sick koi were gills necrosis, kidney erosion and edema,which were similar to the clinical signs of koi herpes virus disease (KHVD).But PCR tests showed negative results for KHV. For further diagnosis, bacterial cultures, transmission electron microscopy studies, virus isolation and PCR tests were used. Electron microscopic observation revealed pox virus particles having a size of about 200 nm×400 nm in the kidney. 548 and 180 bp fragments were amplified from organs of sick koi by PCR method using specific primers of carp edema virus (CEV). The fragments were sequenced and analysed. The results showed that they were shared 100% nucleotide identity with CEV-H504. All the results indicated that this disease was carp edema virus disease, caused by a kind of pox virus, CEV. This was the first report on the CEV of cultured koi in China.